ncicn2012 submission 98

7/31/2019 Ncicn2012 Submission 98

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Continuous Neighbor Discovery Of Asynchronous

Sensor Networks

Arpit Gupta, Ayon Dutta, Debabrata Halder and Indranil Mandal

Internal Guide- Muthaiah. U

Department Of Computer Science

MVJ College Of Engineering

Bangalore India

Abstract-In this project we are working on various sensor nodes and sensor networks. Sensor

nodes are the devices that can sense any event. Sensor networks are the group of sensor nodes

connected to each other via gateway. The sensor nodes are mainly static, but it may fail sometimes

due to excessive power consumption or sometimes due to high voltage, temperature or path breakage.

So the main aim of our project is to transfer the data via sensor nodes efficiently by discovering the

hidden links in a segment or outside the segment and pass the data through those links.

1. IntroductionThe sensor nodes can sense various

events very sensitively. The sensor network

contains very large number of these sensornodes. These sensor nodes may be connected

to each other inside a network by any mesh

structure. Some of the sensor nodes act as

routers and gateways to pass the message

from one particular sensor node to another

sensor node. In order to pass the data there

will be high consumption of bandwidth,

energy and even power.

Therefore we design this project in

such a way that we can minimize these three

critical issues. These issues can be overcome

by alternatively putting the sensor nodes in

active state and passive state. In this paper the

sensor nodes are randomly distributed over a

particular area and each sensor nodes have

certain transmission area to cover. The first

step is to detect the immediate neighbors. The

sensor nodes should have direct wireless

communication between them. Then the

sensor nodes should establish the particular

roots through which they can communicate

with the other sensor nodes via any router or

gateway in between. In order to communicate

we need to first create communication

between two sensor nodes.The sensor nodes

will be awake for a very short period of time.

Therefore there can be heavy traffic in the

channel or in the particular transmission area.

This paper presents a special neighbor

discovery scheme that can be used to reduce

the traffic that is being caused by the sensor

nodes. Another important issue in the sensor

network is that the sensor nodes despite of

being static can change due to the following

situation.

1) Loss of local

synchronization due to accumulated clock

drifts.

2) The ongoing addition of

new nodes, in some networks to compensate

for nodes which have ceased to function

because their energy has been exhausted.

3) The increase in

transmission power of some nodes, in


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response to certain events, su

of emergent situations.

After resolving the

sensor nodes can be there in tis the Init state and the secon

state. Now in this discussion a

discover the links during

operation, and this is re

Continuous Neighbor Discov

have to discuss about how

being discovered by Continu

Discovery algorithm. At first

nodes is in Init state, it remai

very short period of time let

second to T2 second. Now forperiod of time this sensor node

any other sensor node whic

between that specific time

sensor node is active at that p

sensor node repeatedly tran

packets to the next active sen

other sensor node replies back

ACK packet to the previous se

therefore the two way

between the sensor nod

established.

Fig 1. The transmission of HE

in Init and Normal states

The sensor nodes have to be

other nodes by using the joint

nodes. If there is a sensor node

h as detection

our issues the

o states. Oneis the normal

main idea is to

the normal

ferred to as

ery. Now we

the nodes are

ous Neighbor

hen the sensor

ns active for a

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this particularwill search for

is active in

eriod. If any

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mits HELLO

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by sending the

nsor nodes and

ommunication

s is being

LO messages

etected by the

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detected by b with the help

Fig. 2. Continuous neigh

initial neighbor in sen

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Networking:

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networking is the practice

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Networks consist

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be employed to move data from one place to

another, including wires, radio waves, and

even microwave technology.

Network architecture:

Asynchronous Transfer Mode:

Asynchronous Transfer Mode (ATM)

is a switching technique for

telecommunication networks. It uses

asynchronous time-division multiplexing and

encodes data into small, fixed-sized cells.

This differs from other protocols such as the

Internet Protocol Suite or Ethernet that use

variable sized packets or frames. ATM has

similarity with both circuit and packet

switched networking. This makes it a good

choice for a network that must handle both

traditional high-throughput data traffic, and

real-time, low-latency content such as voice

and video. ATM uses a connection-oriented

model in which a virtual circuit must be

established between two endpoints before

the actual data exchange begins.

Network topology

Common layouts

A network topology is the layout of theinterconnections of the nodes of a computer

network. Common layouts are:

A bus network: all nodes areconnected to a common medium

along this medium. This was the

layout used in the original Ethernet,

called 10BASE5and 10BASE2.

A star network: all nodes areconnected to a special central node.

This is the typical layout found in in

a Wireless LAN, where each wirelessclient connects to the central

Wireless access point.

A ring network: each node isconnected to its left and right

neighbor node, such that all nodes

are connected and that each node

can reach each other node by

traversing nodes left- or rightwards.

The Fiber Distributed Data Interface

(FDDI) made use of such a topology.

A mesh network: each node isconnected to an arbitrary numberof neighbors in such a way that

there is at least one traversal from

any node to any other.

A fully connected network: eachnode is connected to every other

node in the network.

Note that the physical layout of the nodes in anetwork may not necessarily reflect the

network topology. As an example, with

FDDI, the network topology is a ring

(actually two counter-rotating rings), but thephysical topology is a star, because all

neighboring connections are routed via acentral physical location.

Overlay network

An overlay network is a virtual computernetwork that is built on top of another

network. Nodes in the overlay are connected

by virtual or logical links, each of which

corresponds to a path, perhaps through many

physical links, in the underlying network.
http://en.wikipedia.org/wiki/Time-division_multiplexinghttp://en.wikipedia.org/wiki/Cell_relayhttp://en.wikipedia.org/wiki/Cell_relayhttp://en.wikipedia.org/wiki/Internet_Protocol_Suitehttp://en.wikipedia.org/wiki/Internet_Protocol_Suitehttp://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/Frame_Relayhttp://en.wikipedia.org/wiki/Frame_Relayhttp://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Latency_%28engineering%29http://en.wikipedia.org/wiki/Connection-orientedhttp://en.wikipedia.org/wiki/Connection-orientedhttp://en.wikipedia.org/wiki/Virtual_circuithttp://en.wikipedia.org/wiki/Virtual_circuithttp://en.wikipedia.org/wiki/Bus_networkhttp://en.wikipedia.org/wiki/Bus_networkhttp://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/10BASE5http://en.wikipedia.org/wiki/10BASE5http://en.wikipedia.org/wiki/10BASE2http://en.wikipedia.org/wiki/10BASE2http://en.wikipedia.org/wiki/Star_networkhttp://en.wikipedia.org/wiki/Star_networkhttp://en.wikipedia.org/wiki/Wireless_LANhttp://en.wikipedia.org/wiki/Wireless_LANhttp://en.wikipedia.org/wiki/Wireless_access_pointhttp://en.wikipedia.org/wiki/Wireless_access_pointhttp://en.wikipedia.org/wiki/Ring_networkhttp://en.wikipedia.org/wiki/Ring_networkhttp://en.wikipedia.org/wiki/Fiber_Distributed_Data_Interfacehttp://en.wikipedia.org/wiki/Fiber_Distributed_Data_Interfacehttp://en.wikipedia.org/wiki/Mesh_networkhttp://en.wikipedia.org/wiki/Mesh_networkhttp://en.wikipedia.org/wiki/Mesh_networkhttp://en.wikipedia.org/wiki/Fiber_Distributed_Data_Interfacehttp://en.wikipedia.org/wiki/Ring_networkhttp://en.wikipedia.org/wiki/Wireless_access_pointhttp://en.wikipedia.org/wiki/Wireless_LANhttp://en.wikipedia.org/wiki/Star_networkhttp://en.wikipedia.org/wiki/10BASE2http://en.wikipedia.org/wiki/10BASE5http://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/Bus_networkhttp://en.wikipedia.org/wiki/Virtual_circuithttp://en.wikipedia.org/wiki/Connection-orientedhttp://en.wikipedia.org/wiki/Latency_%28engineering%29http://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Frame_Relayhttp://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/Internet_Protocol_Suitehttp://en.wikipedia.org/wiki/Cell_relayhttp://en.wikipedia.org/wiki/Time-division_multiplexing


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The topology of the overlay

(and often does) differ fro

underlying one.

A sample overlay network: I

over Optical

For example, manypeer-to-pe

overlay networks because they

as nodes of a virtual system

top of the Internet. The Intern

built as an overlay on the tele

.[14]

The most striking example

network, however, is the Int

the IP layer, each node can r

by a direct connection to t

address, thereby creating a f

network; the underlying netwo

composed of a mesh-like i

subnetworks of varying topol

fact, technologies). Address

routing are the means whi

mapping of the fully-connectnetwork to the underlying ones

Overlay networks have been a

invention of networking w

systems were connected overusing modems, before any

existed.

Another example of an overla

distributed hash table, which

nodes in the network. In

underlying network is an IP n

network may

that of the

P over SONET

rnetworks are

are organized

f links run on

t was initially

hone network

of an overlay

rnet itself: At

ach any other

e desired IP

lly connected

rk, however, is

terconnect of

ogies (and, in

resolution and

h allows the

ed IP overlay.

ound since the

en computer

elephone linesdata network

y network is a

maps keys to

his case, the

twork, and the

overlay network is a tabl

indexed by keys.

Overlay networks have also

a way to improve Internetthrough quality of servic

achieve higher-quality s

Previous proposals such as

and IP Multicast have

acceptance largely becau

modification of all routersi

the other hand, an overlay

incrementally deployed onthe overlay protocol s

cooperation from Internet

The overlay has no control

are routed in the underlying

two overlay nodes, but itexample, the sequence ofmessage traverses befor

destination.

Routers

A router is an

device that forwards

networks by processing inf

the datagram or packet (

information from Layer 3 o

In many situations, thisprocessed in conjunction

table (also known as f

Routers use routing tables t

interface to forward packets

the "null" also known asinterface because data

however, no further proce

said data).

Network security

In the field of networking,

network security[20]

consist

provisions and policiesado

network administrator to pr

monitor unauthorized acces

modification, or denial of th

network and network-acces

Network Security is the aut

access to data in a network,

controlled by the network a

Users are assigned an ID an

allows them access to infor

programs within their auth

Security covers a variety of

e (actually map)

been proposed as

routing, such ase guarantees to

reaming media.

ntServ,DiffServ,

not seen wide

se they require

the network. On

network can be

nd-hosts runningftware, without

ervice providers.

over how packets

network between

can control, foroverlay nodes ae reaching its

internetworking

ackets between

rmation found in

Internet protocol

the OSI Model).

information iswith the routing

rwarding table).

o determine what

(this can include

the "black hole"an go into it,

sing is done for

the area of

of the

ted by the

event and

s, misuse,

e computer

sible resources.

orization of

which is

dministrator.

password that

ation and

rity. Network

omputer
http://en.wikipedia.org/wiki/Peer-to-peerhttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Telephone_networkhttp://en.wikipedia.org/wiki/Computer_network#cite_note-13http://en.wikipedia.org/wiki/Computer_network#cite_note-13http://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Address_Resolution_Protocolhttp://en.wikipedia.org/wiki/Routinghttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/Distributed_hash_tablehttp://en.wikipedia.org/wiki/Distributed_hash_tablehttp://en.wikipedia.org/wiki/Peer-to-peerhttp://en.wikipedia.org/wiki/Peer-to-peerhttp://en.wikipedia.org/wiki/Telephone_networkhttp://en.wikipedia.org/wiki/Telephone_networkhttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Address_Resolution_Protocolhttp://en.wikipedia.org/wiki/Quality_of_servicehttp://en.wikipedia.org/wiki/Streaming_mediahttp://en.wikipedia.org/wiki/IP_Multicasthttp://en.wikipedia.org/wiki/IP_Multicasthttp://en.wikipedia.org/wiki/Routerhttp://en.wikipedia.org/wiki/Routerhttp://en.wikipedia.org/wiki/Internet_service_providerhttp://en.wikipedia.org/wiki/Routerhttp://en.wikipedia.org/wiki/Routerhttp://en.wikipedia.org/wiki/Osi_model#Layer_3:_Network_Layerhttp://en.wikipedia.org/wiki/Computer_network#cite_note-19http://en.wikipedia.org/wiki/Computer_network#cite_note-19http://en.wikipedia.org/wiki/Policieshttp://en.wikipedia.org/wiki/Policieshttp://en.wikipedia.org/wiki/Network_administratorhttp://en.wikipedia.org/wiki/Unauthorizedhttp://en.wikipedia.org/wiki/Quality_of_servicehttp://en.wikipedia.org/wiki/Quality_of_servicehttp://en.wikipedia.org/wiki/Streaming_mediahttp://en.wikipedia.org/wiki/Streaming_mediahttp://en.wikipedia.org/wiki/IntServhttp://en.wikipedia.org/wiki/IntServhttp://en.wikipedia.org/wiki/DiffServhttp://en.wikipedia.org/wiki/DiffServhttp://en.wikipedia.org/wiki/Internet_service_providerhttp://en.wikipedia.org/wiki/Internet_service_providerhttp://en.wikipedia.org/wiki/Packet_%28information_technology%29http://en.wikipedia.org/wiki/Packet_%28information_technology%29http://en.wikipedia.org/wiki/Osi_model#Layer_3:_Network_Layerhttp://en.wikipedia.org/wiki/Osi_model#Layer_3:_Network_Layerhttp://en.wikipedia.org/wiki/Unauthorizedhttp://en.wikipedia.org/wiki/Network_administratorhttp://en.wikipedia.org/wiki/Policieshttp://en.wikipedia.org/wiki/Computer_network#cite_note-19http://en.wikipedia.org/wiki/Osi_model#Layer_3:_Network_Layerhttp://en.wikipedia.org/wiki/Packet_%28information_technology%29http://en.wikipedia.org/wiki/Routerhttp://en.wikipedia.org/wiki/Internet_service_providerhttp://en.wikipedia.org/wiki/Routerhttp://en.wikipedia.org/wiki/IP_Multicasthttp://en.wikipedia.org/wiki/DiffServhttp://en.wikipedia.org/wiki/IntServhttp://en.wikipedia.org/wiki/Streaming_mediahttp://en.wikipedia.org/wiki/Quality_of_servicehttp://en.wikipedia.org/wiki/Distributed_hash_tablehttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/Routinghttp://en.wikipedia.org/wiki/Address_Resolution_Protocolhttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Computer_network#cite_note-13http://en.wikipedia.org/wiki/Telephone_networkhttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Peer-to-peer


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networks, both public and private that are

used in everyday jobs conducting

transactions and communications among

businesses, government agencies and

individuals. Networks can be private, such aswithin a company, and others which might

be open to public access. Network Security is

involved in organization, enterprises, and all

other type of institutions. It does as its titles

explains, secures the network. Protects and

oversees operations being done.

2. Related workIn a Wi-Fi network operating in

centralized mode, a special node, called an

access point, coordinates access to the

shared medium. Messages are transmitted

only to or from the access point. Therefore,

neighbor discovery is the process of having

a new node detected by the base station.

Since energy consumption is not a concern

for the base station, discovering new nodes

is rather easy. The base station periodically

broadcasts a special HELLO message1.

A regular node that hears this

message can initiate a registration process.

The regular node can switch

frequencies/channels in order to find the

best HELLO message for its needs. Which

message is the best might depend on the

identity of the broadcasting base station, on

security considerations, or on PHY layer

quality (signal-to-noise ratio). Problems

related to possible collisions of registration

messages in such a network are addressed in

[4]. Other works try to minimize neighbor

discovery time by optimizing the broadcast

rate of the HELLO messages [1], [5], [6],[7], [8]. The main differences between

neighbor discovery in Wi-Fi and in mesh

sensor networks are that neighbor

discovery in the former is performed only

by the central node, for which energy

consumption is not a concern. In addition,

the hidden nodes are assumed to be able to

hear the HELLO messages broadcast by the

central node.

In contrast, neighbor discovery in

sensor networks is performed by every node,

and hidden nodes cannot hear the HELLO

messages when they sleep. In mobile ad-hoc

networks (MANETs), nodes usually do not

switch to a special sleep state. Therefore,

two neighboring nodes can send messages to

each other whenever their physical distanceallows communication. AODV [9] is a

typical routing protocol for MANETs. In

AODV, when a node wishes to send a

message to another node, it broadcasts a

special RREQ (route request) message. This

message is then broadcast by every node

that hears it for the first time. The same

message is used for connectivity

management, as part of an established route

maintenance procedure, aside from which

there is no special neighbor discovery

protocol. Minimizing energy consumption is

an important target design in Bluetooth [10].

As in Wi-Fi, the process of

neighbor discovery in Bluetooth is also

asymmetric. A node that wants to be

discovered switches to an inquiry scan

mode, whereas a node that wants to discover

its neighbors enters the inquiry mode. In the

inquiry scan mode, the node listens for a

certain period on each of the 32 frequencies

dedicated to neighbor discovery, while the

discovering node passes through these

frequencies one by one and broadcasts

HELLO in each of them. This process isconsidered to be energy consuming and

slow. A symmetric neighbor discovery

scheme for Bluetooth is proposed in [11].

The idea is to allow each node to switch

between the inquiry scan mode and the

inquiry mode.

The 802.15.4 standard [12] proposes a

rather simple scheme for neighbor

discovery. It assumes that every coordinator

node issues one special beacon message

per frame, and a newly deployed node has

only to scan the available frequencies forsuch a message. However, the standard also

supports a beaconless mode of operation.

Under this mode, a newly deployed node

should transmit a beacon request on each

available channel. A network coordinator

that hears such a request should

immediately answer with a beacon of its

own. However, this scheme does not supply

any bound on the hidden neighbor discovery

time.

Neighbor discovery in wireless

sensor networks is addressed in [2]. The


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authors propose a policy for determining the

transmission power of every node, in order to

guarantee that each node detects at least one

of its neighbors using as little power as

possible.In [1], the authors study the problem

of neighbor discovery in static wireless ad hoc

networks with directional antennas. At each

time slot, a sensor either transmits HELLO

messages in a random direction, or listens for

HELLO messages from other nodes. The goal

is to determine the optimal rate of trans-

mission and reception slots, and the pattern of

transmission directions.

In [6], neighbor discovery is studied for

general ad-hoc wireless networks. The

authors propose a random HELLO protocol,

inspired by ALOHA. Each node can be in one

of two states: listening or talking. A node

decides randomly when to initiate the

transmission of a HELLO message. If its

message does not collide with another

HELLO, the node is considered to be

discovered. The goal is to determine the

HELLO transmission frequency, and the

duration of the neighbor discovery process.

In [5], the sensor nodes are supposed

to determine, for every time slot, whether to

transmit HELLO, to listen, or to sleep. The

optimal transition rate between the threestates is determined using a priori knowledge

of the maximum possible number of

neighbors.

In [13], the Disco algorithm is

proposed for scheduling the wake-up times of

two nodes that wish to find each other. For

this algorithm, each node chooses a prime

number; the choice depends on the required

discovery time. Using the Chinese

Remainders theorem, it is proved that the

wake-up periods of the nodes will overlap

within the required time. However, [13] does

not discuss the problem of many sensors in

the same segment collaborating to reduce the

energy they expend for discovering hidden

nodes.

As discussed in Section I, the sensor

network nodes spend most of their time in

sleep/idle mode, where they cannot receive

or transmit messages. Therefore, the nodes

ability to discover a new neighbor is limited

to periods when both are active. In [3], this

neighbor discovery model is shown to be

similar to the well-known birthday paradox.

In our work we use a similar analysis, in

order to find the probability that a node will

be discovered by one of its neighbours.

A novel low-power listening (LPL)

technique, proposed in [14] to overcome

sensor synchronization problems, isimplemented by the B-MAC protocol [15].

The transmission of a packet is preceded by

a special preamble. This preamble is long

enough to be discovered if each node

performs periodic channel sampling.

However, this technique can usually not be

used for initial neighbor discovery, and

cannot be used at all for continuous neighbor

discovery, because it actually requires the

node to stay awake during the entire time it

is searching for a new neighbor.

3. A Basic Scheme AndProblem Definition

Here in this discussion we assume that all

the nodes have same transmission range the

two nodes are set to be connected to each

other only if there is a dedicated link between

the two or there is a set of directly connectednodes between them. The transmission area

of a node is set to be the segment for that

node . Here in this discussion we take care of

four schemes that send SYNC message and

HELLO message to detect the nodes.

Scheme 1. (detecting all hidden link

inside a segment)

A hidden link is the one in which the node

is not directly connected to a node ie there

is no dedicated path between the nodes .In

order to detect the hidden link this

operation can be done by the joint task of

all the others sensor nodes.


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Fig. 3. Segments with hiddlinks

Here in this diagram

the nodes which have a straigthem is a dedicated connecti

lines are hidden links. So from

are connected by a dedicated

connected by hidden link. Th

have to discover the links bet

This is done by the joint task

is directly connected to a.

At first the node a

SYNC message to all the

directly connected to a. The S

tells the neighbours to becomsame time period. Then the

nodes that is being connecte

nodes via dedicated link, will

nodes to become active at the

a. When b becomes active at

period as that of a then a will

messages continuously to b. T

the ACK packet back to a c

request, so the connection i

between a and b and the hidde

discovered by a.

n nodes and

e can see that

t line betweenon and dotted

the figure b, c

link and a, c

erefore now a

ween a and c.

f b and d that

will send the

nodes that is

YNC message

e active at theother sensor

to the other

force the other

time period of

the same time

send HELLO

en b will send

onforming the

s being made

n link is being

Fig 4. Detecting hidden lin

Scheme 2. (Detectingoutside the segment)

In order to detect t

links outside a segment

repeatedly detect all the hi

a segment.

Fig 5. The repeated discove

neighbours

In this diagram u is a hidd

the discovered node. Now

v and then u wants to det

nodes then we have to take

range of v rather then u.

Scheme 3(Neigbhor disco

This model is mai

algorithm used in scheme

of this model is to disc

segment neighbors and to tr

this neighbor. Consider the

ks

all hidden links

e all the hidden

we need to

den links inside

ry of in-segment

n node and v is

hen u discovers

ct other hidden

the transmission

very Model)

ly based on the

1.The objective

ver one of its

nsfer the data to

ollowing fig.


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Fig 6. The neighbor discovery model

From the above fig we can see that A at first

does not send any data. Therefore the NCpacket is empty. When the NC packet is

empty then the A node initiates a data

transfer. Then the data is given to the NC

packet and is buffered. A sends the data to

all the nodes by which it is connected

directly via dedicated link using the

multicast scheme. A then sends the HELLO

packets to all the nodes to which it is

directly connected. A gets the

acknowledgement i.e the ACK packet from

only the neighbor say B. Then A discovers

that B is the immediate neighbor of A and it

then creates a unicast communication

between A and B. When the unicast

communication is being created then the

data present in the NC buffer is being sent to

B. When the data remains in the NC packet

for a longer amount of time without being

transferred then a timeout condition occurs

and the NC packet is declared as stale and so

the delay occurs. Even if after the delay the

NC packet doesnot transmit the data then the

NC packet is timed out and the control goes

back to the condition when the NC packet

was empty.

4. ConclusionWe exposed a new problem in wireless

sensor networks, referred to as ongoingcontinuous neighbor discovery. We argue

that continuous neighbor discovery is crucial

even if the sensor nodes are static. If the

nodes in a connected segment work together

on this task, hidden nodes are guaranteed to

be detected within a certain probability P and

a certain time period T, with reduced

expended on the detection.

We showed that our scheme works

well if every node connected to a segment

estimates the in-segment degree of its

possible hidden neighbors. We then

presented a continuous neighbor discovery

algorithm that determines the frequency

with which every node enters the HELLO

period. We simulated a sensor network to

analyze our algorithms and showed that

when the hidden nodes are uniformly

distributed in the area.

5. References1. The Continuous Neighbor

Discovery In Asynchronous Sensor

Networks - Reuven Cohen and

Boris Kapchits IN IEEE/ACM

TRANSACTIONS ON

NETWORKING, VOL 19, NO 1

FEB 2011

ncicn2012 submission 98

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